CHICAGO: US auto giant Ford said Thursday it will invest $773 million to expand factories across its home state of Michigan, generating 2,350 new jobs, part of a plan to add 12,000 jobs by 2015.

The investment will help save an additional 3,240 jobs, it said.

"Even as we wrap up an incredibly busy year of capacity expansions and product launches, we are continuing to look to the future," Jim Tetreault, Ford vice president of North America Manufacturing, said in a statement.

"These investments, many of which are already under way, will ensure our southeast Michigan manufacturing facilities can support our aggressive growth plans."

The Dearborn-based manufacturer posted its best November since 2005, as sales rose six percent to 177,673 vehicles. The results were driven by strong demand for its small cars, which posted their best November in 12 years.